PB1876: SIXTEEN YEARS OF EXPERIENCE WITH THE MRC-10 PROTOCOL FOR THE TREATMENT OF ADULT ACUTE MYELOID LEUKEMIA IN THE SOUTH OF TUNISIA
Authors: Nour Siala, Yousra Fakhfakh Derbel, Imen Ben Amor, Taicir Rekik, Olfa Kassar, Imen Frikha, Faten Kallel, Maha Charfi, Samia Mnif, Hela Mnif, Khelifa Latifa, Halima Sennenna, Rahma Mallek, Sondes Hadiji Mseddi, Moez Medhaffar, Ali Saad, Moez Elloumi
Journal: HemaSphere (2023)

Topic: 4. Acute myeloid leukemia - Clinical Background: Acute myeloid leukemia (AML) is a serious, but potentially curable hemopathy. Despite the progress of AML treatment in recent decades mainly due to the use of intensives therapies and the improvement of onco-hematological reanimation, this treatment remains disappointing with survivals prolonged by 30 to 40% and a significant risk of relapse in the absence of bone marrow allograft. Aims: We evaluate the therapeutic results of the national protocol inspired by the MRC-10 study in the treatment of adults AML. Methods: From January 2005 to December 2020, we retrospectively studied the outcome of adults, aged 20 to 60 years, with de novo AML treated with the national protocol of AML inspired by the MRC-10 study, in the clinical hematology department of Hedi Chaker Sfax Hospital. Secondary leukemia and FAB M3 were excluded. The classification into two therapeutic groups: favorable and unfavorable, is based on cytogenetic, molecular analysis, and chemosensitivity. Allograft is indicated for patients under the age limit defined according to the period, belonging to the unfavorable group (or favorable group with delayed molecular remission) and having an intra-family HLA-compatible donor. Allograft was performed at the national transplant center of bone marrow. We are interested in the response to treatment: complete remission rate (CRR), failure rate, toxicity-related mortality (TRM), relapse rate, and survival: overall survival (OS), and disease-free survival (DFS). The survival analysis was on the Kaplan-Meier method. Results: We collected 179 patients. The medium age was 40 years, and the M/F ratio was 1.18. The distribution of AML according to the cytogenetic risk group was as follows: 18% low-risk abnormalities, 69% intermediate-risk, and 13% high-risk. The molecular study was feasible only for 51% of cases concluding to CBF-myh11, AML-ETO, and FLT3 in 15%, 11%, and 1 % respectively. Eighty-five percent of patients received Idarubicin during induction, and the remaining received Daunorubicin. CRR after one and two courses were 65% and 68% respectively; it is only correlated with age (P=0.005) and cytogenetic risk group (P<0.0001). The failure induction rate was 16%. The mortality rate during induction therapy was 19%. Severe sepsis was the main cause of death (38%). The therapeutic group was favorable in 36 cases (32%) and unfavorable in 77 Cases (68%). Seventy percent of patients had consolidation by chemotherapy alone. Among the 113 patients in CR and treated according to the protocol, allograft was indicated for 70 patients (62%). The allograft was performed only for 35 patients: 31% (76% of patients with an HLA-compatible donor). The relapse rate was 35%. Relapse is correlated only with the feasibility or not of allograft in CR1 (P=0.03). After a mean follow-up of 100 months, 5 years OS, and DFS were 36%, and 59%respectively. OS was correlated with age at diagnosis (p=0.01), cytogenetic group (p=0.001), and allograft in CR1 (p<0.0001) while DFS was correlated only with allograft in CR1 (p<0.0001). Summary/Conclusion: The therapeutic results of our patients are similar to MRC 10 results in terms of initial failure (16% vs 10%) and survival rate (OS at 5 years was 36% vs 40%). However, our population is characterized by a very high rate of induction death (19% vs 5-10%) and a lower rate of CR after induction (68% vs >80%). Our results can be improved by reducing the death rate by developing of hematological reanimation and by adapting the consolidation treatment according to the prognostic group and the rationalization of the allograft (hoploidentical or unrelated graft). Keywords: Acute myeloid leukemia